1. Field of the Invention
The present invention relates to a method for analyzing Internet telephone quality and its interference. More particularly, an analyzing method for Internet telephone quality and its interference, wherein two-way voice and video quality between IP phones and a measurement instrument is measured using loopback mode of the IP phones and the quality measurement result is delivered to users of the IP phones in a form of audible sound, and, when interference is detected, the internal section of the IP phones and the IP network section are separately analyzed to find the trouble source.
2. Related Prior Art
In recent years, IP phones that deliver voice and video calls through the Internet have been rapidly popularized.
Unlike standard telephones using public switched telephone networks (PSTN) based on circuit switching, IP phones use IP networks based on IP addresses.
IP phones may be divided into wired VoIP (Voice over Internet Protocol) phones and wireless Wi-Fi (wireless fidelity) phones. Reduction in network investment costs due to integration of telephone networks and data networks, reduction in management costs and increase in efficiency owing to construction of integrated networks, and easy adoption of Internet-based multimedia services such as video conferencing are expected to rapidly increase the number of IP phones in the near future.
Unlike the PSTN using dedicated lines, IP networks using flexible lines may experience high packet loss and significant delay depending upon network traffic. In comparison to PSTN telephony, IP telephony tends to be poor in quality of service (QoS) and hence needs more accurate QoS measurement.
That is, VoIP services requiring strict real-time properties may experience significant quality degradation owing to real-time limitations of IP networks. Hence, it is necessary for VoIP service providers to continuously perform quality measurement and interference analysis to resolve customer dissatisfaction due to quality degradation in voice communication and to ensure an effective level of voice communication quality for customers.
As part of an effort to ensure IP telephony quality, in an existing passive monitoring scheme, a monitoring server is installed at a site where a quality problem has occurred or in the middle of the communication path to measure quality and analyze interferences.
More specifically, as shown in FIG. 1, assume that a first IP phone 10 is conversing with a second IP phone 20 through SBC 11a, IP-PBX 12a, IP network 15, SBC 11b and IP-PBX 12b. When a passive monitoring server 16 is installed between the first IP phone 10 and the second IP phone 20 (not at a site where a quality problem has occurred), as quality in between the users is measured (not end-to-end quality), measured quality may differ from the quality perceived by the users. In addition, as the passive monitoring server 16 monitors all data passing through the IP network 15, when a large amount of traffic of many users passes there through, the passive monitoring server 16 may have difficulty in conducting accurate quality measurement and interference analysis owing to heavy load.
As part of an effort to ensure IP telephony quality, in an existing active monitoring scheme, data is sent from a site where a quality problem has occurred to a measurement server and quality measurement and interference analysis are performed on the basis of the amount of damage to the data.
More specifically, as shown in FIG. 2, assume that a first IP phone 30 is conversing with a second IP phone 40 through SBC 31a, IP-PBX 32a, IP network 35, SBC 31b and IP-PBX 32b. When a call originates from a site where quality interference has occurred to an active monitoring server 36 and the active monitoring server 36 measures quality of the call, call quality may be measured only in one direction from the IP phone to the active monitoring server 36 and human intervention may be required to originate a call to the active monitoring server 36. In addition, as measurement and analysis are performed after the time needed for installation from the interference occurrence time, it is difficult to measure and analyze problematic situations in real time.